COLORADO SPRINGS, Colo. – Even those who don't recognize his name will almost certainly know what Travis Tygart has been up to lately.

To put it simply, he's the man who's been making life difficult for Lance Armstrong.

Part teacher and part preacher for his cause, Tygart's official title is chief executive officer of the U.S. Anti-Doping Agency. He's a man who doles out lessons about playing fair while also trying to cajole confessions from those who don't.

His mission: Make sports a sanctuary for finding out which athlete is most talented and has worked the hardest, not who's the best cheater.

Most recently, that mission has led Tygart to spearhead the case that's ended Armstrong's cycling and triathlon careers. Only a year ago, that task seemed even more difficult than out-pedaling him in the Tour de France. Now, Armstrong has been cut loose by his major sponsors and is no longer the face of the Livestrong charity he founded.

As it turns out, the man who became Armstrong's greatest adversary is like him in some ways.

Both Armstrong and Tygart are 41. Like Armstrong, Tygart is in great shape and loves to get on the bike every once in a while.

And like Armstrong, Tygart has a stubborn streak in him. A big one.

"I saw at an early age that working hard is how you become successful," says Tygart, who learned his lessons about teamwork and sports growing up in Florida, where he was on state-championship baseball and basketball teams in high school.

"Playing sports as a kid, I learned all the valuable lessons that I think sports should teach. I'm determined to do everything possible to maintain those lessons for kids growing up."

Tygart has parlayed that credo into a career that, because of his role in taking down one of the world's most famous athletes, has made him among both the most trusted and reviled figures in sports — even if only a small minority of sports fans would recognize him walking down the street.

"I always knew I wanted to do something that made a difference. It was never about anything other than trying to change the world for a better tomorrow," he says, a self-conscious laugh creeping in when he hears how much his words seem like a superhero's catchphrase.

If it all sounds a bit sanctimonious and too good to be true, well, his critics certainly won't argue. To them, he is a hatchet man who ran a witch hunt to settle an old score against Armstrong — a foe who eluded sanctions for more than a decade.

"This isn't about Tygart wanting to clean up cycling," Armstrong wrote in a letter to The Associated Press, before USADA ordered his seven Tour de France titles stripped and before a massive report detailing the evidence against him was released. "Rather it's just a plain ol' selective prosecution that reeks of vendetta."

The case Tygart's agency produced included testimony from 11 former teammates of Armstrong's, along with 15 others, who teamed up to paint the picture of Armstrong as a drug-pushing bully. The report exposed what Tygart calls the most extensive doping program sports has ever seen.

On Wednesday, a week after USADA's documents were released, Armstrong left his post as chairman of his Livestrong foundation, the same day Nike announced it would sever ties with its longtime pitchman.

It was the latest in a steady drumbeat of bad news for Armstrong, all delivered — either directly or indirectly — courtesy of the agency Tygart has led since 2007 when his predecessor, Terry Madden, stepped down.

USADA was formed in 2000 as a way of taking drug cases that were decided by the U.S. Olympic Committee and placing them in the hands of a group that would be run independently. The agency is partially funded by the USOC and partially by the government. It runs on an annual budget of about $14 million and is tasked with finding and catching the drug cheats, spreading the message of clean sports and staying on top of the science in a business where the bad guys are always a step ahead.

As outside counsel, then general counsel, then CEO for USADA, Tygart has worked on every major doping case of the past decade, including the investigation into the Bay Area Laboratory Co-operative, which showed how sophisticated the performance-enhancing drug game had grown and resulted in the prosecution of Barry Bonds.

Among those caught in USADA's net over the years: 2006 Tour de France winner Floyd Landis; Olympic gold medalists Marion Jones and Justin Gatlin; cyclist Tyler Hamilton; all the players listed in the Mitchell Report, which documented doping in baseball and which was put together with Tygart's input. All have had their accomplishments stripped or brought into question.

Through it all, Tygart insists he's treated the so-called celebrity athletes the same way he treats the unknowns — the 40-something marathon runners and teenage in-line skaters who also fall under USADA's purview.

"He states his mission and his vision and you feel it," says Daniel Eichner, the former science director at USADA. "To him, it's all about protecting clean athletes. There's no other agenda."

Very few of the breakthroughs come easy for Tygart, a married father of three, avid skier, runner and, yes, cyclist, who on Tuesday celebrated his daughter's 11th birthday and also his 10th anniversary as a USADA employee.

He always loved the law but wanted some sort of sports connection and says when he sees injustice anywhere, "it's just infuriating, whether it's in sports or other areas of life."

Those who've known him for years say the message doesn't change once the necktie comes off.

"Travis is passionate about sport," said Rich Young, a partner at Bryan Cave LLP, who represents USADA as outside counsel and hired Tygart for that work in 2000. "He's a baseball and basketball player. He's got kids who are athletes. He really gets the difference between true sport and circus."

A native of Jacksonville, Fla., Tygart comes from a family well-respected in the Florida law community. His brother and sister are lawyers. His father was a trial attorney who now works as a mediator. His uncle is a judge. After graduating with a philosophy degree from North Carolina, Tygart returned to Florida and taught high school government classes for three years, while also coaching baseball and basketball. From there, he went to Southern Methodist to get his law degree and begin the path toward becoming the single most powerful man in the U.S. anti-doping game.

Much has been made of death threats he received during the Armstrong investigation. Why does he keep on going?

"Because I've heard the stories from the athletes," he says. "I've heard them from the clean athletes who left their sport and felt personally robbed."

He thinks of lifelong friends such as T.R. Lewis, who had major league potential but never made it. Lewis came up during the 1990s — the steroids era — and got aced out by players he knew were using performance-enhancing drugs. He says looking at the Mitchell Report "is like someone leafing through their high school yearbook. It's all these guys I played with, played against."

"I don't mean to overstate my presence in the game, but I joke with Travis that, in some regard, I'm the poster boy for the players who got left behind," Lewis said.

And Tygart is their faithful servant.

The CEO said he was confused in February, when federal prosecutors abruptly decided not to charge Armstrong and drop a nearly two-year investigation. "You'll have to ask them why they shut down," is all he'll offer when pressed on the subject.

He was irritated when the feds refused to share their evidence with USADA, as had been customary in similar instances in the past.

Instead of quitting, Tygart hit the phones and revved back up on his own investigation. Unlike the feds, he did not need to tie Armstrong to criminal activity, much of which allegedly occurred in Europe. He needed to show that the cyclist broke the rules of sport.

Months later, Armstrong was charged under USADA's rules. The cyclist opted in August not to fight the accusations, still denying he used performance-enhancing drugs but saying the arbitration system was rigged against him.

Tygart went ahead and banned Armstrong from competition and ordered that race results back to 1998 be erased. Then his agency released its report on the case.

"At the end of the day, the truth is too powerful, whether it was this case or any other," Tygart said. "And at the end of the day, the truth was revealed."